1. Field of the Invention
The present invention relates to a pallet, and more particularly to a pallet that transfers a liquid crystal display device in a fabrication process line of the liquid crystal display device.
2. Description of the Related Art
Generally, a liquid crystal display (hereinafter, referred to as “LCD”) device is a representative flat panel display device which controls the transmittance of light beam to correspond to video signals, thereby displaying a picture. Especially, the LCD device is on a trend of its application scope being broadened due to characteristics such as lightness, thinness, lower power consumption drive and the like. According to such a trend, the LCD device is used in office automation devices and the display devices of notebook computers.
FIG. 1 is an exemplary diagram representing a liquid crystal display panel of a liquid crystal display device of the related art, and FIG. 2 is a flow chart representing a fabrication process of the liquid crystal display device of the related art.
That is to say, as shown in FIG. 1, a liquid crystal display panel 10 of the liquid crystal display device includes a thin film transistor (hereinafter, referred to as “TFT”) substrate 11 for receiving drive signals; a color filter (hereinafter, referred to as “C/F”) substrate 12 inclusive of a color filter layer; and a liquid crystal layer 13 interposed between the TFT substrate and the C/F substrate.
The whole fabrication process of the liquid crystal display device inclusive of the liquid crystal display panel 10 described above, as shown in FIG. 2, is divided into a substrate fabrication process S202, a liquid crystal display panel process S204, a liquid crystal display panel inspection process S206 and a module process S208.
First of all, the substrate fabrication process S202 is divided into a process of fabricating the TFT substrate in use of a cleaned glass substrate and a process of fabricating the C/F substrate. The TFT substrate fabrication process is a process of forming signal lines, a plurality of thin film transistors and pixel electrodes on a lower glass substrate. The C/F substrate fabrication process is a process of sequentially forming a black matrix, a color filter layer and a common electrode ITO on an upper glass substrate.
Next, the liquid crystal display panel process S204 is a process of fabricating the liquid crystal display panel by bonding the TFT substrate and the C/F substrate together and by injecting liquid crystal therebetween. Generally, a plurality of liquid crystal display panels are formed in one original plate. The liquid crystal display panel process is made up of many unit processes such as an alignment film forming process, a rubbing process, a cell gap forming process, an assembly process, a cell cutting process, a liquid crystal injecting process, a grinding process and the like.
Next, the liquid crystal display panel inspection process S206 is a process of inspecting whether wires are down and whether there are dot defects and the like for the liquid crystal display panel which have been through the cell cutting process and the grinding process in the liquid crystal panel process. And, the liquid crystal display panel inspection process is confirmed personally by a user's eyes in use of an auto probe AP.
Lastly, the module process S208 is a final process of linking the liquid crystal display panel and a signal process circuit part, and the liquid crystal display device is completed by the module process.
FIG. 3 is an exemplary diagram representing a process line of the module process of the related art, and shows the module process S208 in detail. Further, FIG. 4 is an exemplary diagram representing a usage state of a flat pallet of the related art, and each process shown in FIG. 3 is performed for the liquid crystal display device put on the flat pallet.
At this moment, each process part shown in the drawings is connected through a conveyor, and each process will be briefly explained as follows.
Firstly, a liquid crystal display panel loading section 31 is for loading the liquid crystal display panel which has been through the liquid crystal display panel inspection process S206.
A TAB process section 32 is a place where a polarizer, a TCP and a PCB are combined with the liquid crystal display panel inputted by the loading section 31, and the polarizer, the TCP and the PCB can be manually combined by a plurality of workers or automatically combined by a robot and the like. At this moment, in order to prevent the damage from impurities, a resin is spread over data pads and gate pads formed on the TFT substrate of the liquid crystal display panel, and the TCP and the PCB are stuck onto the pads in use of an ACF being an anisotropic conductor.
A backlight joining section 33 is a place where the liquid crystal display panel and the backlight unit are joined. The backlight unit is configured to include a cover bottom which is of a plate shape and is formed of a metal or synthetic resin material; a reflector which is placed on the cover bottom, is of a plate shape and is formed of a metal material having a white or silver color; a plurality of lamps arranged in parallel on the reflector; and an optical sheet part placed on the lamps.
A top case combination section 34 is a place where a top case is combined with the upper part of the liquid crystal display panel in a state that the liquid crystal display panel is joined with the back light unit, and screws and the like are combined therewith so as for the top case and the liquid crystal display panel not to be separated.
A protection film adhesion section 35 is a place where a protection film is stuck thereto to protect the surface of the liquid crystal display panel which is combined with the top case, and is for preventing the surface damage of the liquid crystal display panel from being generated during the following process.
A reversal section 36 is a place for turning over the upper surface and the lower surface of the liquid crystal display device to which the protection film is stuck in the liquid crystal display panel in the state that the liquid crystal display panel is combined with the backlight unit. That is to say, the process up to the protection film adhesion section 35 is made in the state that the C/F substrate of the liquid crystal display panel, i.e., the surface of the liquid crystal display panel to which a picture is substantially outputted, faces upward.
A backlight combination section 37 is for completely combining the backlight unit and the liquid crystal display panel with the screws and the like while the upper surface of the backlight unit faces upward by the reversal section 36. And, an operation that the components of the backlight unit and the liquid crystal display panel are put into a support main and the like is simply made in the backlight joining section 33, and the components are completely combined by the backlight combination section 37.
A cable connection section 38 is a place for connecting various electrical cables and the like to the PCB substrates formed in the rear surface of the backlight unit which faces the upper surface.
An aging section 40 is a place for confirming whether there is a defect of the liquid crystal display device made by the processes above, and the liquid crystal display device is operated under a designated condition, e.g., for 4 hours in a space of 50° C., to be checked.
A final inspection section 41 is a place for confirming whether there is a defect of the product which has been through the aging section 40. The liquid crystal display device having been through the process in the final inspection section 41 is packed to be shipped out after finally completing the inspection.
Herein, the processes from the backlight joining section 33 to the backlight combination section 37 are called a pre-process in the assembly process of the related art, and the processes from the cable connection section 38 to the final inspection section 41 are called a post-process.
On the other hand, as described above, each process section is connected through a conveyor and the process in each process section is made in a flat pallet 60, as shown in FIG. 4.
That is to say, in the backlight joining section 33, the top case combination section 34, the protection film adhesion section 351 the reversal section 36, the backlight combination section 37, the cable connection section 38 and the like, as shown in FIG. 4, operators perform a process which is necessary in each process after locating the liquid crystal display device 70 on the flat pallet 60.
At this moment, in the process to the protection film adhesion section 35, the liquid crystal display panel faces upward and each process is performed in a state that the backlight unit is closely adhered to the flat pallet 60. However, in the backlight combination section 37, as shown in FIG. 4, each process is performed in a state that the liquid crystal display panel to which a protection film 71 is stuck is in contact with the flat pallet 60 for the combination of the backlight unit part, the connection of cables and the like.
On the other hand, the process is performed in the state that the liquid crystal display panel is in contact with the flat pallet 60 as described above in the backlight combination section 37, thus there is a problem in that inferior products might be generated because scratches are generated in the liquid crystal display panel by the friction with the flat pallet 60 and particles and the like formed on the flat pallet surface. Accordingly, in order to solve the above-mentioned problem in the related art, the liquid crystal display panel to which the protection film is stuck by the reversal section 36 is made to be in contact with the flat pallet 60, as shown in FIG. 4, after sticking the protection film 71 onto the surface of the liquid crystal display panel by the protection film adhesion section 35.
However, in order to stick the protection film 71, the component of the protection film is additionally required as well as a space like the protection film adhesion section 36 is required in the process, thus there is a problem in that there is a limit in space and a production cost is increased.
Further, there is a problem in that a labor cost is increased because operators for sticking the protection film 71 are additionally required.
Further, in the post-process, the final inspection should be carried out after removing the protection film 71 again, and especially, stains might be generated due to the protection film adhesion for performing the process in the aging section 40 which carries out the process of operating the liquid crystal display device at a high temperature. And, additional operators might be required in accordance with the re-adhesion of the protection film and the additional process due to the problem of there being generated a phenomenon that the protection film comes apart while being in the aging section or during the post-process.